Workpieces, including food parts, are cut or otherwise portioned into smaller portions by processors in accordance with customer needs. Also, excessive fat, bone, or other foreign or undesirable materials are routinely trimmed from the food products. It is usually desirable to portion and/or trim the food products into uniform sizes or shapes, for example, for steaks to be served at restaurants or chicken filets used in frozen dinners or in chicken burgers.
The portioning/trimming of workpieces, in particular food products, is now carried out with the use of high-speed portioning machines. These machines use various scanning techniques to ascertain the size and shape of the food product as it is being advanced on a moving conveyor. This information is analyzed with the aid of a computer to determine how to most efficiently cut the food product into optimum portions, trim excessive fat, remove bones, etc. The food product is then portioned or trimmed by various cutting devices, including high-speed liquid jet cutters or rotary or reciprocal blades. Once the portioning/trimming has occurred, the resulting portions are off-loaded onto a take-away conveyor for further processing, or, perhaps placed in a storage bin.
The cutters which do the portioning/trimming have a set length of time to operate since the workpiece is being carried by a continuously moving conveyor. The speed of the conveyor dictates the time in which the cutting devices have to complete the necessary portioning/trimming. If the workpiece is conveyed too fast, the portioner will not have enough time to finish the prescribed portioning/trimming operations. In the past, the conveyor belt speed has been set manually so that the conveyor operates continuously at a single/fixed speed. However, such speed may be too fast to complete the portioning/trimming operations, and thus leading to not cut workpieces as noted above, or too slow, which results in loss of production capacity. The present invention seeks to address this problem by automatically adjusting the speed of the conveyor to maximize the portioning machine's throughput while achieving an acceptable level of workpieces that are not cut.